The major superoxide dismutase of the unicellular red alga, Porphyridium cruentum, has been purified to homogeneity. This enzyme has a molecular weight of 40,000 and is composed of two subunits of equal size, which are joined by noncovalent interactions. Manganese constituted 0.13% of this superoxide dismutase. T,is is equivalent to 1 manganese atom/molecule of enzyme. Cyanide at 5 mM and H2O2 ...

effects of yeast extract (ye) (0, 0.05, 0.1, 0.2, 0.5 and 1%) were investigated on rosmarinic acid (ra) accumulation and tyrosine aminotransferase (tat) gene expression in melissa officinalis seedlings at different time intervals (4 and 17 hours). based on the results, only ye concentrations of 0.05%, 0.1%, and 0.2%, for the 17-hour treatment, significantly stimulated ra biosynthesis pathway. a...

Isoniazid (INH) activation in vitro is associated with reduction of the mycobacterial ferric KatG catalase-peroxidase by hydrazine and reaction with O2 to form an oxyferrous enzyme complex. Since this complex could also form directly via reaction of ferric KatG with superoxide, intracellular activation might be responsive to superoxide concentration. When Mycobacterium smegmatis carrying the M....

Transfection of a human pSV2 (copper-zinc) superoxide dismutase expression vector into murine fibroblasts resulted in stable clones producing increased amounts of copper-zinc superoxide dismutase. A marked increase in endogenous glutathione peroxidase activity (up to 285%) and a smaller increase in glutathione transferase activity (up to 16%) also occurred. Manganese superoxide dismutase activi...

Three constitutive forms of superoxide dismutase activity have been demonstrated in the cyanobacterial marine picoplankter Synechococcus sp. WH 7803 using polyacrylamide gel activity staining techniques. A protein which gave a positive non-haem iron stain on native polyacrylamide gels exhibited N-terminal similarity to both the iron superoxide dismutase and the manganese superoxide dismutase of...

BACKGROUND The mucosal pathology of Helicobacter pylori infection may in part be due to excessive production of reactive oxygen metabolites (ROMs) by phagocytes. The influence of H pylori infection on mucosal superoxide dismutases, some major scavenger enzymes of ROM was investigated. In humans superoxidase dismutase is present in at least two forms-that is, mitochondrial manganese (Mn)-superox...

Heat stress is associated with death and other maladaptions including muscle dysfunction and impaired growth across species. Despite this common observation, the molecular effects leading to these pathologic changes remain unclear. The purpose of this study was to determine the extent to which heat stress disrupted redox balance and initiated an inflammatory response in oxidative and glycolytic...

Arterial baroreflex sensitivity is attenuated in chronic heart failure (CHF) state, which is associated with cardiac arrhythmias and sudden cardiac death in patients with CHF. Our previous study showed that CHF-induced sodium channel dysfunction in the baroreceptor neurons was involved in the blunted baroreflex sensitivity in CHF rats. Mitochondria-derived superoxide overproduction decreased ex...

The intracellular localization of Cu,Zn superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) has been examined by immunofluorescence using four monoclonal anti-Cu,Zn superoxide dismutase antibodies raised against a recombinant human Cu,Zn superoxide dismutase derivative produced and purified from Escherichia coli. Colocalization with catalase, a peroxisomal matrix enzyme, wa...

Highly purified iron superoxide dismutase was obtained from Escherichia coli B using a modification of the procedure of Yost and Jridovich (Yost, F. J., Jr., and Fridovich, I. (1973) J. Biol. Chem. 248, 4905-4908). The protein contained 1.8 +/- 0.2 atoms of iron per 38,700 g of protein. We have found that cyanide does not bind to the Fe3+ ion of iron dismutase but fluoride and azide have modera...